A wide variety of implantable medical devices (IMDs) that deliver a therapy to or monitor a physiologic or biological condition of a patient, or both, have been clinically implanted or proposed for clinical implantation in patients. The IMD may deliver therapy to or monitor a physiological or biological condition with respect to a variety of organs, nerves, muscles or tissues of the patients, such as the heart, brain, stomach, spinal cord, pelvic floor, or the like. The therapy provided by the IMD may include electrical stimulation therapy, drug delivery therapy or the like.
A patient in which the IMD is implanted is generally recommended to avoid sources that may interfere with operation of the IMD. These sources of interference may be medical sources or non-medical sources. One example medical source of interference is magnetic resonance imaging (MRI), which is an imaging technique to visualize the internal structure and function of the body. MRI systems typically use a strong static magnetic field, a varying gradient magnetic field, and radiofrequency (RF) pulses used to produce an image. Subjecting the IMD to such an environment may cause inappropriate operation of or damage to the IMD.